The Interaction Among Mesoscale Dynamics, Microphysical Properties and Radiative Effects of Mid-latitude Cirrus Clouds

中纬度卷云的介尺度动力学、微物理性质和辐射效应之间的相互作用

• 批准号: 1144017
• 负责人: Thomas Ackerman
• 金额: $ 54.61万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1144017&HistoricalAwards=false
• 关键词: Interaction; Among; Mesoscale; Dynamics; Microphysical

Cirrus clouds form under a variety of dynamical and thermodynamical conditions, and have a profound impact on the radiative energy balance of the Earth. The radiative properties and the radiative impact of cirrus clouds are inherently controlled by their microphysical and macrophysical properties. However, the physical and dynamical mechanisms that govern the formation, microphysical evolution, and the life cycle of cirrus clouds and influence their mesoscale variability are not very well understood, which in turn hinders confident quantification of the radiative impact of cirrus under various conditions. The primary goal of this research is to significantly improve our understanding of the linkages between the microphysical and macrophysical properties of mid-latitude cirrus clouds and the dynamical and thermodynamical properties of the air masses in which they form. We seek to provide a detailed and process-based understanding of the links between the large scale and mesoscale dynamical forcing, the microphysical and macrophysical properties of cirrus clouds and their radiative properties. The methodology used in this study combines (1) numerical simulations with a cloud-resolving regional model; with (2) a novel dynamical state classification technique to cluster cirrus cloud events according to large scale and mesoscale dynamical forcing; and (3) comparison of simulated cirrus cloud properties with observations from aircraft and remote sensors.The cloud-resolving regional model simulations allow for a detailed and process-based investigation of the microphysical and macrophysical properties of cirrus clouds, as well as provide deeper insight into the physical and dynamical mechanisms that affect the evolution and life cycle of cirrus and the mesoscale dynamical feedbacks that are caused by the presence of cirrus. The atmospheric state classification technique enables us to statistically link atmospheric dynamical states with the microphysical and macrophysical characteristics of cirrus clouds, allowing us to draw physically and statistically based conclusions regarding how cirrus cloud properties are affected by different large scale and mesoscale dynamical forcings. The results of the classification are crucial for evaluating and improving cirrus microphysical parameterizations in a regime dependent approach. Comparison of model simulations with observations makes use of an unprecedented data set of new microphysical observations in mid-latitude cirrus clouds.Intellectual merit Substantially improved understanding of the microphysical and dynamical controls of cirrus clouds and a better understanding of how these controls affect the macrophysical and radiative properties of mid-latitude cirrus will be obtained. This knowledge will be invaluable for improving microphysical parameterizations and lead to a more physically based representation of cirrus microphysical, macrophysical, and radiative properties in numerical models on various scales. The improved representation of cirrus cloud properties will then help to better quantify the radiative impact of mid-latitude cirrus.Broader impacts Graduate education and training, collaboration with other scientists, improvement of microphysical parameterization and representation of cirrus clouds in cloud-resolving regional models, and participation in international model inter-comparisons are all planned in this work. Newly acquired data sets and results will be archived and shared with the broader research community. Our research results will be documented in peer-reviewed publications and disseminated through our participation in and presentations at national and international workshops and conferences. In addition we will engage underrepresented minority students in our research and use elements of the data analysis in curriculum development for undergraduate and high school students.

卷云在各种动力和热力学条件下形成，并对地球的辐射能量平衡产生深远的影响。卷云的辐射特性和辐射影响受其微观物理和宏观物理特性的内在控制。然而，控制卷云形成、微物理演化和生命周期并影响其中尺度变异性的物理和动力学机制还不是很清楚，这反过来又阻碍了对各种条件下卷云辐射影响的可靠量化。这项研究的主要目标是显著提高我们对中纬度卷云的微物理和宏观物理特性与形成它们的气团的动力和热力学特性之间的联系的理解。我们试图对大尺度和中尺度动力强迫、卷云的微物理和宏观物理特性及其辐射特性之间的联系提供详细的和基于过程的理解。这项研究中使用的方法结合了(1)数值模拟与云分辨区域模式；(2)根据大尺度和中尺度动力强迫对卷云事件进行分类的新的动力状态分类技术；以及(3)模拟的卷云特性与来自飞机和遥感的观测结果的比较。云分辨区域模式模拟允许对卷云的微物理和宏观物理特性进行详细和基于过程的调查，并提供更深入的物理和动力学机制，影响卷云的演化和生命周期以及由卷云的存在所引起的中尺度动力反馈。大气状态分类技术使我们能够在统计上将大气动力学状态与卷云的微物理和宏观物理特征联系起来，使我们能够得出基于物理和统计的结论，即不同的大尺度和中尺度动力强迫如何影响卷云的特性。分类结果对于评估和改进依赖区域的卷云微物理参数化是至关重要的。模式模拟与观测的比较利用了前所未有的中纬度卷云微物理观测的数据集。智力优势将极大地提高对卷云微物理和动力学控制的理解，并更好地理解这些控制如何影响中纬度卷云的宏观物理和辐射特性。这一知识对于改进微物理参数化将是非常有价值的，并导致在不同尺度的数值模式中更基于物理的卷云微物理、宏观物理和辐射特性的表示。卷云属性的改进表示将有助于更好地量化中纬度卷云的辐射影响。这项工作计划包括研究生教育和培训、与其他科学家的合作、改进微物理参数化和卷云在云分辨区域模式中的表示，以及参与国际模式的相互比较。新获得的数据集和结果将被存档，并与更广泛的研究界共享。我们的研究成果将记录在同行评议的出版物中，并通过我们参加国家和国际讲习班和会议并在其上发言来传播。此外，我们将让少数族裔学生参与我们的研究，并在本科生和高中生的课程开发中使用数据分析的元素。